1. Field of the Invention
The present invention relates generally to a training paddle for swimming, and more specifically to a training paddle that encourages a swimmer to use an efficient curvilinear stroke path.
2. Description of the Prior Art
The use of swim paddles as a means of improving upper body strength in swimmers is widely acknowledged. Such swim paddles are conventionally releasably attached to the swimmer's hands, and are used to increase the drag to which the swimmer is exposed while swimming.
Existing swim paddles are flat, and have a variety of shapes, some being square, some oval, and even some triangular in shape. Swim paddles are typically held on the swimmer's hand by a surgical tubing positioned through the paddle to form a finger loop. Sometimes a portion of surgical tubing is also used to secure the swimmer's wrist to the paddle in a similar manner. The ends of the tubing may extend through the paddle and protrude from the under surface of the paddle. Examples of existing paddles are shown in U.S. Pat. Nos. 5,376,036; 5,288,254; 4,913,418; and Re. 28,855.
A curvilinear stroke path has been found to be preferable to a straight stroke path. A curvilinear stroke path creates higher propulsive forces than a straight stroke path, and encourages a longer stroke length, both identified as necessities to swimming at a high level of competition.
The freestyle swimming stroke ideally includes several phases, shown schematically in FIG. 1, with the insweep portion and the upsweep portion providing the majority of the propulsive forces. In general, the hand enters the water and moves through the downsweep and catch portion A of the stroke to position the hand and arm for the insweep and upsweep phases of the stroke. During the insweep portion B of the stroke, the hand moves inward, upward and backwards to the midline of the body, during which time water passes across the hand from the thumb to the little finger. The hand is held at an angle and deflects the water away from the hand in a sculling motion, rather than pushing the water straight backwards. During the inward move, the swimmer feels lift and considerable hand pressure from the water. Those swimmers who are most efficient (elite v. non-elite) in sculling (propelling efficiency) are likely to perform at greater speeds. It is not strength or power generated that makes a faster swimmer, rather it is a swimmer's efficient engagement of the water that makes one swim faster.
After the insweep phase has been completed, the hand and arm move through the upsweep phase D where the fingertips are pointing toward the bottom of the pool and the palm faces backwards. In the upsweep phase, the water passes along the hand from the palm to the fingertips (outward, upward, and backward). A sculling action is also used in the upsweep phase where the hand is moved in diagonal skulls from side to side and not strictly backwards. The upsweep phase creates the highest propulsion and the majority of the forward movement experienced during the freestyle stroke.
After the upsweep portion of the stroke, the hand moves through the release portion E of the stroke where the hand and arm are positioned to leave the water. The elbow and hand actually leave the water during the recovery portion of the stroke, and the arm is brought forward to begin the stroke again.
The use of the presently available flat swim paddles do not facilitate the swimmer's use of the efficient sculling freestyle stroke just described because of the flat shape of the paddles. Flat paddles generate their greatest propulsive forces when the flow of water is perpendicular to the paddle, as shown in FIG. 2. When the flow of water is perpendicular to the paddle, the propulsive force results from drag. The swimmer finds the greatest propulsive force by pulling straight back, and so does not utilize the optimal curvilinear stroke path. The flat paddles are drag-dominant, creating a straighter sculling motion. Additionally, strength or propulsive forces are not what separate the elite swimmers. Rather, its the propelling efficiency of the swimmer, which results from a more efficient curvilinear stroke path. The use of the conventional flat paddle also shortens the swimmer's stroke as a result of the straight stroke path.
The sculling motions used in the insweep and the upsweep portions of the curvilinear freestyle stroke are known to generate a mixture of lift and drag in the swimmer's hand. In a study of Olympic swimmers, commentators have found that the most efficient swimming stroke for generating the highest speed for a swimmer includes the curvilinear stroke, and that lift and drag forces are about equally important in generating propulsion in the freestyle stroke. Propulsive Techniques: Front Crawl Stroke, Butterfly, Backstroke, and Breaststroke, Swimming Science V, 1988, at 53-59; Human Kinetics Publishers, Inc., R. E. Schleihauf, J. R. Higgins, R. Hinrichs, D. Luedtke, C. Maglischo, E. Maglischo and A. Thayer. It has been shown that the curvilinear stroke path allows for a higher propelling efficiency allowing a swimmer to use lower forces to achieve faster velocities. Lift in combination with the drag created by the movement of the swimmer's angled hand through the insweep and upsweep portions of the stroke motion, as opposed to drag alone, are believed to be key in generating a higher velocity using lower forces. It has also been found that the stroke length of the swimmer is also an important factor in generating a high velocity while swimming. Three-Dimensional Analysis of the Men's 100-m Freestyle During the 1992 Olympic Games, Journal of Applied Biomechanics, 1995, at 103-112, Human Kinetics Publishers, Inc., J. M. Cappaert, D. L. Pease, and J. P. Troup.
There is a need in the art for a swim training paddle designed to utilize a combination of lift and drag forces and to encourage the use of the curvilinear stroke path in the freestyle stroke. It is to overcome these shortcomings in the prior art that the present invention was developed.